Plant Hormones

Q.

What is the main function of auxin?

Q.

Write a note of functions of abscisic acid.

Q.

What is a plant hormone? Name four plant hormones. State one function of each.

Q. What are the exact functions of the plant hormones(Auxin, Cytokinins, Gibberellins, Abscisic acid)?

Q.

What is stimulus

Q.

What causes a green plant exposed to the light, on only one side, to bend towards the source of light as it grows?

1. Auxin accumulates on the shaded side, stimulating greater cell elongation there

2. Light stimulates plant cells on the lighted side to grow faster

3. Green plants seek light because they are phototropic

4. Green plants need light to perform photosynthesis

Q. On touching leaves of mimosa pudica, it droops down- Explain

Q.

What is parthenocarpic fruit? Give example.

Q. Which of the following hormone promotes cell division in plants?

1. Cytokinins
2. Gibberellins
3. Auxin
4. Abscisic acid

Q.

Which of the following is a plant hormone?

1. thyroxin

2. cytokinin

3. insulin

4. oestrogen

Q.

The plant hormone which triggers the fall of mature leaves and fruits from the plant body is:

(a) auxin

(b) gibberellin

(c) abscisic acid

(d) cytokinin

Q. Describe briefly the mechanism of stomatal movement. [4 MARKS]

Q.

Question 12
Which of the following is not associated with growth of plants?

(a) Auxin
(b) Gibberellins
(c) Cytokinins
(d) Abscisic acid

Q.

Which of the following is not a plant hormone ?

(a) auxin

(b) ascorbic acid

(c) cytokinin

(d) abscisic acid

Q. What is hypocotyl?

Q.

The phenomenon of falling of leaves and the fruits from the plant is known as abscission.

1. True

2. False

Q. Give three examples of reflex actions.

Q.

Which plant hormone is named anti-ageing hormone?

Q. Which of the following is a gaseous plant hormone?

1. Auxin
2. Cytokinin
3. None of these
4. Ethylene

Q.

Select the growth inhibitor among the following:-

1. IAA

2. GA

3. Ethylene

4. Abscisic acid

Q.

Plant appears to bend towards light due to:

1. Concentration of auxins at shoot tip.

2. Concentration of auxins at root tip.

3. Diffusion of auxins towards the shady side of root.

4. Diffusion of auxins towards the shady side of shoot.

Q.

A higer concentration of ethylene is found in :

(a) green banana (b) ripe banana

(c) fresh potato tuber (d) green apple

Q.

Functions of auxin.

Q.

Which plant hormone promotes cell division and cell differentiation along with auxin?

1. Auxin

2. Insulin

3. Cytokinins

4. Gibberellins

Q.

Who isolated Auxin first?

Q. ‘X’ and ‘Y’ are plant hormones which inhibits growth and promotes ageing in plants respectively. Identify ‘X’ and ‘Y’.

1. X - Cytokinin Y - Auxin
2. X - Abscisic acid Y - Ethylene
3. X - Auxin Y - Cytokinin
4. X - Ethylene Y - Gibberellin

Q.

Name the following :

(a) Hormone that stimulates growth by cell-division.

(b) Growth retarding hormone in plants.

(c) Main auxin found in most plants.

Q.

Which plant hormone causes the ripening of fruits?

1. Ethylene
2. Cytokinin
3. Auxin
4. Gibberellin

Q. The hormone called is used to produce seedless fruits.

1. auxin
2. gibberellin
3. cytokinin
4. ethylene

Q. Which phytohormone is known as the stress hormone and why?